The Teensy 3.0 I ordered is on its way. In the meantime I have some questions.

- is there a forum for the Teensy 3.0 or is this thread the best place to ask questions?- I notice in the Beta5 IDE Tools menu that you can choose one of three CPU speeds - e.g. to overclock at 96MHz. Is this selection all you need to do or do you also have to make some sort of hardware change?- I'd like to play around with the ARM's DSP instructions. Is there any support to allow use of them in a sketch or do I have to get my hands dirty with assembler?

Sadly, the Raspberry Pi has a bootloader bug that makes it incompatible with some cards.

Somewhat off topic, but just FWIW, the R-Pi has been reported to show about 20 MB/sec both reading and writing to a "SanDisk Extreme SDHC 4GB class 10" according to http://elinux.org/RPi_Performance#SD_card Somewhere around June/July 2012 there were some bug-fixes to the SD card I/O routine firmware in the R-Pi, which improved compatibility with several different types of cards. Most cards perform slower than the above example.

- I notice in the Beta5 IDE Tools menu that you can choose one of three CPU speeds - e.g. to overclock at 96MHz. Is this selection all you need to do or do you also have to make some sort of hardware change?

My experiments indicate that the menu selection alone does in fact change the clock speed, nothing else required. See for example http://dangerousprototypes.com/forum/viewtopic.php?f=2&t=4606#p45080

I tried a benchmark of my own using a function which computes the bearing between two locations specified as lat/long. It produces essentially the same kind of timing as seen before.In summary, compared to a Duemilanove (=2009) the result of calling the function 10000 times is:2009 @ 16MHz 12.57secsT3 @ 48MHz 8.30 secsT3 @ 96MHz 7.82 secs

The interesting thing I noted was the difference in the size of the code.The Duemilanove code is 4764 bytes whereas the T3 code is 19984 bytes! I presume that the T3 is hauling in different libraries but it seems to be a bit excessive. OTOH it is 19984 bytes of a 131,072 byte maximum so there's plenty of room to spare :-)